1. Field of the Invention
The present invention relates to a scrubber, and in particular to a scrubber for filtering out siliciferous byproducts from waste gas.
2. Description of the Related Art
FIG. 1 shows a conventional scrubber used in semiconductor factories. The scrubber 10 is connected to a gas inlet pipe 1, a gas outlet pipe 2, a water inlet pipe (not shown) and a drainpipe 5. The gas inlet pipe 1 is connected to the inlet 11 near the lower portion of the scrubber 10. The gas outlet pipe 2 is connected to the outlet 12 at the top portion of the scrubber 10. The drainpipe 5 is connected to the bottom portion 13 of the scrubber 10. The conventional scrubber 10 has a plurality of sprayers 14 connected to the water inlet pipe to spray water into the scrubber 10. The nebulized water 141 humidifies the waste gas (Gin) introduced from the gas inlet pipe 1 to catch siliciferous particles (Si, Si3N4) and dissolve corrosive gas (NH4, SiH2Cl2, SiH4) produced during semiconductor processes. Wastewater is then discharged from the drainpipe 5 and treated by a sewage treatment system.
The conventional scrubber 20 sprays water to remove siliciferous particles and corrosive gases, however, some particles still pass through the chamber with the gas flow and enter the gas pipe because they are too small (about 1 xcexcmxcx9c5 nm) and light. These sub-micron particles are either deposited in the exhaust pipe, or discharged into the atmosphere, as airborne contamination, causing air pollution.
Hence, there is a need for a dependable air scrubber to filter most of siliciferous particles and corrosive gases from the waste gas discharged from semiconductor equipment.
Accordingly, an object of the invention is to provide a modified scrubber to filter siliciferous byproducts suspended in the corrosive waste gas discharged from semiconductor process. The scrubber further keeps sub-micron particles from being deposited in the exhaust pipe, decreasing the running cost.
Moreover, corrosive gases used in semiconductor processes can be dissolved in the water and treated by a sewage treatment system. Thus, air pollution caused by the waste gas is reduced.
The present invention provides a scrubber connected to a gas inlet pipe and a water inlet pipe. The scrubber comprises a chamber and a water-injecting device. The chamber has an outlet, an inlet connected to the gas inlet pipe, and a plurality of sprayers connected to the water inlet pipe to spray water into the chamber. The water-injecting device is disposed at the outlet and connected to the water inlet pipe. The water-injecting device has an annular gap and injects water to provide a first water film over the outlet of the chamber, flushing out the particles from the waste gas.
According to the embodiment, the water-injecting device has an outer pipe wall and an inner pipe wall with a gap to provide the first water film. Water is introduced from the water inlet pipe through the space between the outer pipe wall and inner pipe wall.
Moreover, the water-injecting device also has a waterspout disposed in the center of the inner pipe wall above the first water film, providing a second water film over the outlet of the chamber. The chamber further includes a water outlet to drain water from the chamber.
A detailed description is given in the following embodiments with reference to the accompanying drawings.